.\" -*- nroff -*-
.\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
.\"
.TH IBV_BIND_MW 3 2016-02-02 libibverbs "Libibverbs Programmer's Manual"
.SH "NAME"
ibv_bind_mw \- post a request to bind a type 1 memory window to a memory region
.SH "SYNOPSIS"
.nf
.B #include <infiniband/verbs.h>
.sp
.BI "int ibv_bind_mw(struct ibv_qp " "*qp" ", struct ibv_mw " "*mw" ",
.BI "                struct ibv_mw_bind " "*mw_bind" ");
.fi
.SH "DESCRIPTION"
.B ibv_bind_mw()
posts to the queue pair
.I qp
a request to bind the memory window
.I mw
according to the details in
.I mw_bind\fR.
.PP
The argument
.I mw_bind
is an ibv_mw_bind struct, as defined in <infiniband/verbs.h>.
.PP
.nf
struct ibv_mw_bind {
.in +8
uint64_t                     wr_id;           /* User defined WR ID */
unsigned int                 send_flags;      /* Use ibv_send_flags */
struct ibv_mw_bind_info      bind_info;       /* MW bind information */
.in -8
}
.fi
.PP
.nf
struct ibv_mw_bind_info {
.in +8
struct ibv_mr                *mr;             /* The MR to bind the MW to */
uint64_t                     addr;            /* The address the MW should start at */
uint64_t                     length;          /* The length (in bytes) the MW should span */
unsigned int                 mw_access_flags; /* Access flags to the MW. Use ibv_access_flags */
.in -8
};
.fi
.PP
The QP Transport Service Type must be either UC, RC or XRC_SEND for bind operations.
.PP
The attribute send_flags describes the properties of the \s-1WR\s0. It is either 0 or the bitwise \s-1OR\s0 of one or more of the following flags:
.PP
.TP
.B IBV_SEND_FENCE \fR Set the fence indicator.
.TP
.B IBV_SEND_SIGNALED \fR Set the completion notification indicator.  Relevant only if QP was created with sq_sig_all=0
.PP
The mw_access_flags define the allowed access to the MW after the bind
completes successfully. It is either 0 or the bitwise \s-1OR\s0 of one
or more of the following flags:
.TP
.B IBV_ACCESS_REMOTE_WRITE \fR Enable Remote Write Access. Requires local write access to the MR.
.TP
.B IBV_ACCESS_REMOTE_READ\fR   Enable Remote Read Access
.TP
.B IBV_ACCESS_REMOTE_ATOMIC\fR Enable Remote Atomic Operation Access (if supported). Requires local write access to the MR.
.TP
.B IBV_ACCESS_ZERO_BASED\fR If set, the address set on the 'remote_addr' field on the WR will be an offset from the MW's start address.
.SH "RETURN VALUE"
.B ibv_bind_mw()
returns 0 on success, or the value of errno on failure (which
indicates the failure reason).  In case of a success, the R_key of the
memory window after the bind is returned in the mw_bind->mw->rkey field.
.SH "NOTES"
The bind does not complete when the function return - it is merely
posted to the QP. The user should keep a copy of the old R_key, and
fix the mw structure if the subsequent CQE for the bind operation
indicates a failure. The user may safely send the R_key using a send
request on the same QP, (based on QP ordering rules: a send after a bind
request on the same QP are always ordered), but must not transfer it to the
remote in any other manner before reading a successful CQE.
.PP
Note that for type 2 MW, one should directly post bind WR to the QP,
using ibv_post_send.
.SH "SEE ALSO"
.BR ibv_alloc_mw (3),
.BR ibv_post_send (3),
.BR ibv_poll_cq (3)
.BR ibv_reg_mr (3),
.SH "AUTHORS"
.TP
Majd Dibbiny <majd@mellanox.com>
.TP
Yishai Hadas <yishaih@mellanox.com>
